Turkey's army has blamed Kurdish fighters for a deadly car bombing that killed two of its soldiers in the country's Kurdish-dominated southeast.

Four other troops were wounded in the attack on Saturday night in Diyarbakir province .

The military said the Kurdistan Worker's Party (PKK) fighters also fired on the troops in the attack, which it called a "treacherously pre-planned" ambush.

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While the army blamed the PKK, no group has yet claimed responsibility for the explosion.

The attack came amid ongoing military campaigns, which began on Friday, one against the Islamic State of Iraq and the Levant (ISIL) group across the border in Syria, and the other targeting PKK in northern Iraq.

The air raids followed a suicide bombing in the southern Turkish town of Suruc earlier in the week that killed dozens of Kurdish activists.

Turkish authorities blamed ISIL for that attack.

Ahmet Davutoglu, Turkish prime minister, has said the military operations would not have a time-frame, indicating a prolonged offensive.

The PKK said Turkish strikes on its bases meant the government in Ankara had ended a fragile 2013 ceasefire between the two sides.

PKK has for decades waged an armed campaign in Turkey's southeast that claimed tens of thousands of lives.

A peace process that began in 2013 has so far failed to yield a final deal.

Merkel's appeal

In a related development, German Chancellor Angela Merkel's office said on Sunday that she had a phone conversation with Davutoglu, urging him to stick with the Kurdish peace process despite the recent escalating violence.

Merkel assured Davutoglu of the "solidarity and support of Germany in the fight against terrorism" but also recalled "the principle of proportionality in the implementation of necessary measures", Georg Streiter, Merkel's spokesperson, said in a statement.

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The chancellor appealed to Davutoglu "not to give up the peace process with the Kurds but to continue it despite all the difficulties", the statement said.

Some in the Turkish opposition say they are concerned the governing AK Party's aims with new attacks on the PKK to stir up anti-Kurdish sentiment before a possible early election later this year.

The AK Party has until late August to find a junior coalition partner or face an early election.

It lost its single-party majority for the first time in more than a decade in June, in large part due to the success of the pro-Kurdish Peoples' Democratic Party (HDP), which entered parliament for the first time.

"One of the aims of the air, land and media operations carried out right now is to undermine the HDP in early elections," Selahattin Demirtas, the HDP head, said on Twitter.

The PKK says Turkish strikes on its bases mean the government has ended a 2013 truce between the two sides [Getty Images]

Source: Al Jazeera and agencies